This invention relates to a suspension arm assembly for a heavy duty vehicle with air suspension, and more particularly, the invention relates to a modular suspension arm assembly suitable for various spring heights and pinion angles.
Suspension assemblies supporting an axle assembly are connected to a vehicle frame by suspension arms. For heavy duty vehicle air suspension assemblies, particularly, for coach and bus applications, numerous suspension arms are used to increase stability to the vehicle and improve ride characteristics. In places where suspension arms are used, typically one is required at each xe2x80x9ccornerxe2x80x9d of the axle assembly. Usually, the drive input for bus and coach application is at an angle and to accommodate this, the axle is tilted to the required angle, but the pads where the airbags are mounted are at the same height from the ground. As a result, up to four unique castings may be required for a particular suspension assembly.
The suspension arms define a spring height and pinion angle for the suspension assembly. Bus and coach vehicles typically require more than one spring height and more than one pinion angle. Typically, the pinion angle is given when the axle is tilted to achieve the required pinion angle. As a result, the suspension arm mounted at the front and rear of the axle have an angle and a height difference. Current technology requires a saint air bag pad height to achieve this. Accordingly, numerous castings for the suspension arms are required for the different suspension assemblies, in addition to the different castings for each suspension assembly, which greatly increase the cost of the suspension assembly. Therefore, what is needed is a modular suspension arm assembly that is suitable for accommodating various spring heights and pinion angles.
The present invention provides a heavy-duty vehicle suspension assembly including an axle assembly having opposing suspension arm mounting faces. A pair of modular suspension arm assemblies are secured to the axle assembly with the suspension arm assemblies extending outwardly from the axle assembly in opposite directions from one another. Each suspension arm assembly includes a first arm portion having a first end secured to the mounting face and extending to a second end. A second arm portion is secured to the second end and has a spring seat with a spring supported on each of the spring seats of the suspension arm assemblies for damping forces transmitted through the axle assembly. The first and second arm portions include mounting surfaces that overlap one another in a plurality of positions to permit the arm portions to be secured to one another in a plurality of configurations that accommodate numerous spring heights and pinion angles.
The first and second arm portions may be constructed as separate castings. Once the desired spring height and pinion angle have been determined, the arm portions are oriented relative to one another in a configuration to obtain the desired spring height and pinion angle. The arm portions are secured to one another to retain the arm portions in the configuration, such as by drilling holes and using fasteners to secure the arm portions to one another.
Accordingly, the present invention provides a modular suspension arm assembly that is suitable for accommodating various spring heights and pinion angles.